AT THE OFFICE OF MARKS AND PATENTS OF THE UNITED STATESSYSTEM AND METHOD TO REMOVE PRESSURIZED GAS.
BACKGROUND OF THE INVENTION1. Field of the Invention This invention concerns a pressurized gas delivery system and particularly a method and a set of instruments used to transfer natural gas ("CNG") from a supply station to one or more vehicles with storage tanks. 2. The Description of Related Art Since the systems for compressing and dispensing natural gas are well known, for example, the United States Patent Numbers have already been published: 3,837,377; 4,515,516; 4,527,600; 4,966.2C6; 5,029,622; 5,169,295; 10 5,238,030; 5,259,424; and 5,351, 726. Because of the interrelation that already exists between temperature, pressure and volume of gases, the amount of CNG that can be safely introduced into a storage tank such as that of a vehicle during refueling necessarily depends on factors such as the volume and pressure of the tank design, and the temperature and pressure of the gas inside the tank. The industrial convention states that the degree of pressure for the CNG fuel tanks at the standard temperature of 70 F, as well as the pressure degrees such as 2400, 3000 and 3600 psi correspond to an internal gas temperature of 70 F. During the recharge fast, the internal temperature of the tank will rise 'typically up to 70 F due to the adiabatic compression of the gas. After the tank has been filled, the temperature and pressure inside the tank will normally decrease as the gas cools. Wide variations in ambient temperature above or below the standard condition of 70 F can also have a significant effect on the pressure indicated inside the tank during and after recharging. In addition to safety considerations, the effects of temperature and pressure on the volume of gas delivered during recharging are also important for billing or accounting costs. Previously CNG recharge systems have used various devices and methods to regulate the cut-off pressure and to determine the amount of gas dispensed during the recharging of vehicle storage tanks. The US publications 3,837,377 disclose the means for sensing the pressure of a certain amount of reference gas contained in a reference pressure vessel that is in thermal contact with the tank being filled. The gas is loaded into the tank and the pressure in both the reference vessel and the tank is controlled and compared. The recharge ends when there is a predetermined pressure differential between the gases in the reference vessel and in the tank. The use of an internal reference vessel increases manufacturing and installation costs and also presents a continuous maintenance problem with respect to monitoring the integrity of the reference vessel. If the reference vessel leaks, there is no way to verify that the reference pressure is correct and has not changed. On the other hand, the use of a reference vessel such as that published in the USA. No. 3,837,377 will not provide a response time as fast as desired in which the gas ratio will be gradually reduced as the receiver tank pressure begins to reach the reference pressure. THE USA 4,527,600 discloses a CNG dispensing system comprising a high pressure storage tank from which the CNG flows through a control valve, a pressure regulator and a flow sensor transducer to the tank being filled. The temperature and pressure transducers in the storage tank transmit electrical signals to a process control computer that calculates the volume of gas delivered by comparing the initial and final values of the CNG to the interior of the storage tank. A differential pressure cell that communicates with the storage tank and the filling line of the vehicle tank generates a signal that the computer uses to operate a valve controlled by a solenoid placed in the filling line. The flow continues until the pressure in the vehicle storage tank reaches a predetermined point of adjustment, causing the regulator to close. The set point of the regulator is not, however, adjusted according to the temperature inside the tank of the vehicle. THE USA 5,029,622 defines a gas recharging device and an operating method in which at least one temperature sensor is used to sense the ambient air temperature external to the recharging device and generate a first real value signal while the sensor of Pressure senses the pressure of the gas flow in the distribution means and generates another signal of real value in the response to what is mentioned here. It has been said that an advantage of this recharging device is that of establishing real values between pressures and temperatures in short time intervals with the set of permissible values being corrected according to the development of the previous measures. However, here again, the temperature inside the vehicle storage tank is not controlled during recharging. The USA 4,966,206 refers to another device for recharging tanks with CNG that automatically adjusts the fill pressure of the gaseous fuel to the local ambient temperature. A temperature sensor is placed on the cover of the device to generate a signal with respect to the ambient temperature. A pressure difference sensor is connected to the suction line of the compressor to generate a signal in response to the gas inlet pressure. A pressure difference sensor is also provided to generate a signal in response to a difference in pressure between the fuel pressure in the inlet line of the case cover and the pressure inside the casing. A control device arranged in the case cover is connected to each of the three sensors in order to receive signals from them. This control device is also connected to the inlet valve and to the discharge valve in order to control them in response to the signals received from the sensors. The USA 5,238,030 talks about a pressurized fluid dispensing system that can automatically compensate the gas temperature in non-standard environments, until ensuring a complete filling of a pressurized storage tank. The temperature and pressure transducers connected to the source (supply of a total measurement) measure the stagnation of the temperature and pressure of the CNG, and a pressure transducer in fluid communication with the tank of the vehicle by means of the connection of the Dispatch hose is used to determine the pressure in the vehicle tank. A second temperature transducer is used to measure the ambient temperature. An electronic control system, connected to the temperature and pressure transducers and to the control valve connection, calculates a pressure cut in the vehicle tank based on the ambient temperature and on the degree of pressure of the same, which has It has been pre-programmed into the electronic control system and automatically cuts the CNG flow when the pressure in the vehicle tank reaches the calculated cut-off pressure. US 5,259,424, related to the US. 5,238,030, refers to a similar system in which the pressure transducer is used to determine the discharge pressure; in which case the electronic control system calculates the volume of the tank of the vehicle and the additional mass of CNG required to increase the tank pressure to the cut-off pressure; and within which the CNG flow is interrupted when the additional mass has been dispatched to the mobile tank.
SUMMARY OF THE INVENTIONUnlike the systems mentioned in the previous operations that measure the pressure inside a reference vessel, the ambient temperature or the temperature of the gas being dispensed, the present system consists of measuring the temperature both inside a receiving tank as in a CNG storage tank mounted on a vehicle. According to a certain particularity of the invention, a pressurized gas delivery system comprises a source of pressurized gas, a receiver tank; the means to monitor the temperature inside the tank and the pressure of the gas introduced into the tank; a computer programmed to read the vehicle identification number as well as the volume of water in the tank, information on temperature and pressure, to calculate volumes, pressures and temperatures for the gas based on that data, and to control the flow of pressurized gas in response to said data and calculated values; the means to digitize and transmit the vehicle identification number, the tank water volume and the temperature and pressure information to the computer; as well as the means to selectively control the flow of gas from the pressurized gas source to the receiver tank. According to a certain particularity of the invention, a conventional thermocouple or other equipment for measuring temperature is installed to sense the temperature changes near the center of the tank. In a particular CNG recharge vehicle system, tank temperature data is communicated through the vehicle data module to the computer that controls the dispatch system. Another particularity of the invention is that, the tank temperature data is transmitted to the computer through a firm connection using a connector installed in the vehicle. According to another feature of the invention, a method for dispensing pressurized gas from a pressurized gas source to a receiving tank is offered, the method comprising the steps to connect the tank to the pressurized gas source by means of a detachable gas flow pipe.; receiving and storing in a computer the information corresponding to the volume of water and the maximum pressure value of the tank; calculate the volume of gas that the tank can hold at nominal pressure and at 70 F; the reading of the temperature and the initial pressure of the tank; calculate and store the initial volume of gas in the tank, estimate the final temperature and pressure; calculate and store the initial volume of gas in the tank; estimate the temperature and final pressure; start the flow of pressurized gas to the tank; monitor the actual temperature of the tank and the gas pressure; recalculate the volume of gas in the tank; determine if the volume of gas in the tank is less than or equal to the standard cubic feet of gas that the tank can support at nominal pressure; and interrupting the flow of pressurized gas in the tank when the volume of gas in the tank reaches the desired level in relation to the standard cubic feet of gas that the tank can withstand at nominal pressure. According to some particularity of the invention, the receiver tank is quickly filled until the tank pressure is within 200 psi of the estimated final pressure, and then it is filled more slowly until the filling is completely complete and the flow gas is suspended. With the system and method disclosed herein, the computer repeatedly adjusts the estimated final pressure, necessary to compensate for any adiabatic heat gain during the recharging process. This technique ensures that each recharged tank receives the maximum fuel load safely, which preferably will not exceed the maximum operating pressure recommended by the manufacturer. At no time during the dispatch cycle shall the pressure inside the receiver tank exceed the maximum allowable pressure recommended by the manufacturer for that tank. It is preferable to determine the volume of gas dispensed during recharge as the difference between the initial and final gas volume inside the receiver tank as calculated by the system computer. Other optional aspects of the invention of the automated vehicle filling system include, automatic vehicle identification and authorization for recharging; a succession of valves to maximize the filling speed by reducing the flow velocity as the final pressure is reached; show the current driving range in miles based on the MPG calculated since the last recharge; the ability to measure the volume of gas delivered in any desired unit, including standard cubic feet (SCF), British thermal units (BTU), therms, decatherms, gallon equivalents of gasoline (GGE); and a determination of the cost or charge for the gas delivered. According to another feature of the invention, a system and a method are disclosed for simultaneously "slow filling" or "filling time" to be applied to a variety of receiver tanks with a pressurized gas by a variety of hoses connected to a single multiple. Such a system could be used, for example, by a fast operator in situations where numerous vehicles are stored and serviced in a common maintenance area. With this particularity of the invention, a hose is preferably connected to each vehicle when it is parked in the recharging area and recharging continues until the receiving tanks in all the vehicles have reached the desired pressure level. When the tanks are filled slowly according to this particularity of the invention, any gain in adiabatic heat gained inside the tank during the recharge is dissipated through the wall of the tank in such a way that the internal temperature of the tank remains close to the ambient temperature and does not it is necessary to adjust the estimated final pressure to compensate for the gain in adiabatic heat. Instead, the estimated final pressure is determined by adjusting the maximum operating pressure recommended by the manufacturer for the tank under standard conditions to the extent that the ambient temperature varies from 70 F during recharging. In this application of the invention, the transducers are preferably placed to measure temperature and pressure inside each receiver tank allowing the calculation of initial and final gas volume under standard conditions. This invention replaces the conventional sonic CNG dispenser and micro motion equipment at a much lower unit cost. Conventional dispensing and measuring equipment is limited to a very narrow range of flow rates. In the best case, the micro-motion dispatcher and the measuring equipment demonstrate an accuracy of plus or minus two percent of the actual mass of gas delivered. This accuracy can only be maintained within a fairly narrow flow velocity range of roughly 33 percent of its design capacity. If the unregistered gas rate exceeds the design capability of the measurement system, the gas must be sealed by means of a choke. Also, if the gas velocity flows at the lower limit of acceptable accuracy, the gas flow must be interrupted until sufficient gas pressure is reached to give a flow velocity within the accuracy range. Because the system disclosed here does not need to measure the gas flow rate, it is completely independent of any flow rate restriction. Therefore, it can measure the volume of gas transferred at any speed and is only limited in accuracy by the devices used to measure the initial and final temperature and pressure of the gas inside the vehicle's fuel tank.
BRIEF DESCRIPTION OF THE DRAWINGS.
The system in question and its method of operation are described below and explained in relation to the following figures of the drawings where: FIG. 1 is a simplified schematic view of a particular feature of the invention of the pressurized gas dispensing system adapted to be used as a CNG recharging system in motor vehicles, it also shows two alternate configurations of apparatus for the transmission of temperature and pressure data from the receiver tank to the system computer; FIG.S. 2A, 2B, 2C and 2D together comprise a simplification of the flow block diagram illustrating the steps of the CNG recharging method of the invention as described in the system of FIG. 1; FIG. 3 is a simplified schematic view of another particular characteristic of the compressed gas dispensing system of the invention adapted to be used in the slow filling of a variety of receiver tanks with a pressurized gas such as the CNG; FIGS. 4a, 4B and 4C collectively comprise a simplification of a flow block diagram illustrating the steps of the method of the invention as practiced using the system of FIG. 3 to recharge with pressurized gas such as the CNG, vehicle storage tanks; FIG.5 is a detail cut-away view of an end of a receiver tank suitable for the use of the present invention. It shows a thermowell and a thermocouple installed on the end of the tank opposite the gas inlet.
FIG. 6 is a front elevation and elevation view of the thermowell illustrated in FIG. 5, with the thermocouple wires going out of the thermowell: FIG. 7 is a detail view in sectional and elevation cut taken along line 7-7 of FIG. 6, describing the end of the inner face of the thermowell of FIGS. 5 and 6, showing the location of the thermocouple bed in relation to the inner wall of the thermowell; FIG. 8 is a detail elevation view of a particularity of the hose connector assembly for the use of the invention, the assembly having an RF loop antenna is used to transmit information on vehicle identification and temperature data. and pressure from the vehicle to the computer that controls the recharge of the system; and FIG. 9 is a simplified schematic view of another particularity of the compressed gas dispensing system of the invention adapted for use in the slow filling with CNG of a variety of vehicle storage tanks.
DESCRIPTION OF OWN PARTICULARITIESReferring to FIG. 1, the system 10 of the invention preferably comprises the pressurized gas source 12 connected to the receiver tank 14 by a pressurized gas flow line 16 and a removable hose connection assembly 18; gas supply valve, three-way vent valve 45 and a pressure transducer 24 housed in the gas flow pipe 16 to control the flow of pressurized gas between the gas source 12 and the receiver tank 14; the temperature transducer 22 housed inside the receiver tank 14; the analog to digital converters 26, 36; the computer system 38; and screen 40. The gas supply valve 20 is preferably a two position valve that is selectively opened and closed by solenoids 28 which act electronically in response to signals received from the computer 38. A typical response time for the valve 20 It is around 120 microseconds. The Solenoid 28 can be wired to the computer 38 as illustrated in FIG. 1 or if desired it can be activated by a remote transmitter. Although the main use of the system and method of the invention is to recharge the storage tanks in vehicles with compressed natural gas, it will be evident when reading the specification of the present system that is equally useful for recharging other types of gas storage tanks., with pressurized gas. The source of pressurized gas 12 may be a large volume storage tank, a pressurized gas supply line, a compressor discharge line, or any combination of these elements suitable for use in the supply of gas to a receiving tank 14 in the amount and pressure large enough to achieve the filling speed, filling level and pressure desired. A particular gas source 12 for supplying pressurized gas to a receiver tank 14 is a system such as that shown and described in U.S. 5,351, 726, which is incorporated herein by reference. It should be understood for purposes of the present invention that the source of pressurized gas 12 can include both the fast and slow filling sources, which together with the equipment to control the source from which the gas is supplied in response to the signals generated by the computer 38. The term "quick fill" generally applies fill rates in excess of 200 cfm per tank, while the term "slow fill" is generally understood to apply at fill rates of less than 200 cfm per tank, and generally for flow rates of around 30 cfm per tank or less. It will of course be appreciated that the terms relating to "rapid filling" and"slow filling" and that the flow rates associated with these terms may vary considerably according to the capacity of the gas supply pipe and according to the number and volume of the receiving tank (s) to be filled in. a particular application. The flow rates mentioned above are exemplary of those that can be reasonably used in the "fast filling" or "slow filling" of storage tanks in vehicles such as pick-ups or CNG automobile storage tanks. For systems such as the one described herein in relation to the particularities of the invention,"Fast filling" is used mainly when a single tank is recharged, as described herein with reference to FIGS. 1 and 2, while "slow filling" is mainly used when simultaneously recharging a variety of tanks as described with reference to FIGS. 3, 4 and 9. The three-way venting valve 45 and a selected assembly of the hose connection 18 (disconnected) preferably comprises a male connector 56 communicating with the supply pipe of the vehicle tank 58 connected to the panel. of the vehicle 60 by the nut 62, and female connector 54 equipped with a spring connected to the gas flow line 16. The female connector 54 and the male connector 56 preferably have integral check valves (not visible in FIG. remains open when the connection is made. The three-way vent valve 45 is preferably installed on the dispensing island or on the refill spring upstream of the hose connection assembly 18. The valve 45 preferably has the valve body 82 containing a part that is activated rotating the knob 84 to selectively establish fluid communication between the gas flow pipe 16 and either between the tank supply pipe 58 or the vent pipe 88, or alternatively, to interrupt the fluid communication between the pipeline gas flow 16 and the supply tank pipe 58. By selectively turning the valve knob 84 to the venting position after recharging, the operator is able to relieve the gas pressure within the set 18 of the hose connector that allows the decoupling between the female connector 54 and the male connector 56. The three-way vent valve 45 and the connector assembly hose 18 with its quick connection (conforming to the requirements of the NGV II rules) are commercially available in houses well known to the industry such as Staubli, Swagelok, Parker Hannefin and Hoke Gyrolok. According to a particularity of the invention, the two RF antennas 42, 44 are connected by male and female connectors 56,54, respectively, as well as the hose connector assembly 18 is connected, the two RF antennas are close to one of the another so that the transfer of the data can be carried out as will be discussed in more detail later. The pressure transducer 24 is preferably placed in the gas flow pipe 16 between the supply valve 20 and the three-way vent valve 45 and generates a signal corresponding to the pressure in the pipeline that is transmitted by the analog converter. - to - digital 36 to the computer 38. Once the gas flow pipe 16 has been put in fluid communication with the receiver tank 14 connecting the hose connector assembly 18 and by manual opening of the valve 45, and before the valve 20 is opened, the pressure transducer 24 is capable of measuring the initial pressure in the receiver tank 14 (although the initial pressure in the receiver tank 14 rises slightly when the valve 45 is opened after the connection of the Hose connector set 18). An important aspect of the present invention is the arrangement of the temperature transducer 22 inside the receiver tank 14. The chosen temperature transducer 22 for use in the current invention is described below and is explained in relation to FIGS. 5-7. Referring to FIGS. 5-7, it is preferable that the temperature transducer 22 be made of stainless steel 304 and secured by a thread 66 to a hole in the rear wall of the receiving tank 14 that is opposite the fuel inlet port 43 as shown in FIG. 1. It is preferable that the free end of a portion of the probe 64 of the temperature transducer 22 extends into the receiver tank 14 to a point at or near the centroid of the tank, or at least along the line of tank centers, in order to obtain temperature data that are representative of the temperature of the gas inside the tank. Referring to FIGS. 6 and 7 it is preferable that the portion of the probe 64 of the temperature transducer 22 is a tubular member with a blind side with a relatively thin thickness when compared to the thickness of the wall of the receiving tank 14. The cable 68 comprises electrical conductors 70 72, it is preferable that it extend inside the probe portion 64 and that the cables 74, 76 connected to the conductors 70, 72 respectively, be joined to each other in the insulator bead 78, which is also grounded at the internal surface of the bottom of the wall 80 of the portion of the probe 64. The measurement of the temperature inside the receiving tank 14 offers several advantages over the previous systems. With the system disclosed herein, the volume of gas inside the receiver tank 14 and the desired final pressure can be determined or recalculated by the computer 38 at any time based on the actual temperature of the gas inside the receiver tank 14. term "the final pressure" as used herein, refers to the pressure inside the receiver tank 14 when the gas filling level is in a predetermined range preferably within 1.5% of the standard volume condition to the value of The standard condition of maximum pressure for the tank. With a commercially available pressure transducer having a quarter percent accuracy and a thermocouple with an accuracy of plus or minus 4 F, then the combined error should be only, for example, around 1.1 percent at 3,000 psi. At no time during the dispatch cycle the actual pressure inside the receiver tank shall not exceed the maximum pressure recommended by the manufacturer for that tank. The signal from the temperature transducer 22 can be transmitted to the computer 38 by any of the different commercially available conventional systems. Three alternative equipment are described in a diagram in FIG. 1. In two of the alternatives described in FIG. 1, the temperature data signal generated by the temperature transducer 22 is first channeled to the analog-to-digital converter 26 and the vehicle data module 32. (Although shown separately in FIG 1, it is understood that that converter 26 can be a part of the circuitry of the vehicle data module 32.) According to a certain particularity of the invention, the signal for the digitized temperature data is directed through an RF transmitter 34, to the antenna 42, and then captured by the antenna 44 and directed through the RF receiver 46 to the computer 38. According to another particularity of the invention referring again to FIG.1 the signal from the temperature transducer 22 can alternatively be routed to the computer system 38 by a firm connection that uses removable connections interconnectable to the vehicle 50 and the connection of the control system 52, both are schematically described with a line 48. The connections 50, 52 may be constructed in the respective male and female connectors 56, 54 of the hose connector assembly 18 or may be located at any other point reasonably accessible to the operator during recharging. According to another particularity of the invention referring again to FIG. 1 the signal from the temperature transducer 22 can alternatively be directed to the computer of the system 38 by means of a firm connection using detachable connections interconnectable to the vehicle 92 and the connection of the control system94 and through the analog-to-digital converter 96, which are schematically described on dotted line 90. The connections 92, 94 can be formed with their respective male and female connector 56, 54 of the hose connector assembly 18 or can be located at any other point reasonably accessible to the operator during recharging.
In CNG recharge operations authorized as a point of sale or safe fuel pumps in a fast self-service operation can be controlled by a credit card or a "key card" system. With some previous systems, each employee or client is provided with a magnetic card and assigned a personal identification number ("PIN"). After examining the magnetic card, the person requesting fuel is asked to enter their PIN number. The PIN number helps prevent unauthorized use of the magnetic card, but does not prevent the use of unauthorized fuel. For example, an employee who has a magnetic card and a PIN number can supply an unauthorized vehicle or an unauthorized auxiliary container even with the key card system installed. In the best of chaos, keeping track is difficult, particularly if the vehicles are rotated or reassigned to other operators. It is desirable that the CNG reloading system 10 disclosed here, is aptly adapted to incorporate the vehicular point of sale authorization feature that eliminates any data handling by the employee. According to a particularity of the invention it is desirable that the vehicle data module of each vehicle be programmed to transmit to computer 38 a discrete alphanumeric identification code such as, for example, the number of 14 characters given by the manufacturer for identification of the vehicle. vehicle. The volume of water, the maximum allowable pressure and the maximum operating pressure for the receiving tank 14 can also be transmitted to the system 38 computer at this point if it has not yet been stored in the computer's memory of the system (or as cross check against the values stored in the memory). The transmitted code must match one of a list of pre-authorized codes in the computer of the system 38 in order to start the recharge cycle, which provides a very reliable security against unauthorized use. In addition, the vehicle data module can be programmed to transmit additional information to the system computer, such as the odometer readings for gasoline driven mileage or through CNG power, engine hours for both fuels and the . According to a particularity of the invention, the transmitter, the receiver and the antennas used for this purpose are the same, transmitter 34, receiver 46 and the antennas 42, 44 described above for the use of temperature data transmission to the receiver tank 14. distance to avoid errors is preferably controlled so that the communication between the vehicle and the fuel hose is broken if the fuel hose is disconnected from the vehicle. The communication between the vehicle and the fuel hose is continuously controlled during the refueling and the fuel dispenser shuts down if the signal is lost. This prevents the system from dispatching CNG to anything other than an authorized vehicle. Alternatively, if a connection system represented within dotted line 48 of FIG.1 is used to transmit temperature data to the computer system 38 through the vehicle data module 32, then other information such as the vehicle identification data, tank water volume, pressure ranges of the manufacturer, and the As, they can be transmitted to the system 38 computer using this data link. The relationship between pressure, volume and temperature for a CNG is governed by the Law of Ideal Gas corrected for the super compressibility of natural gas, which can be stated as follows: P = ZnRT V Where: P = pressure Z = supercompressibility factor n = number of moles of gas present R = Universal Constant for Gas T = temperature (R) V = cubic feetThe present invention takes into account the actual temperature inside the receiver tank 14 and uses the computer 38 to continuously adjust the final recharge pressure to compensate for the adiabatic heat gain during the recharge process. The computer 38 preferably receives the initial temperature from the transducer 22 to the interior of the tank 14 and the initial pressure from the transducer 24, and then calculate the initial volume of the gas in the tank 14 using the equation:Vi = P, Zb TbVt Z, T, PbWhere: V = volume of gas in the receiver tank at the beginning of the recharge (SCF) P, = gas pressure in the receiver tank at the beginning of the recharge (PSIA) Z = supercompressibility factor of the CNG in base conditions Tb = temperature base (520 ° R) Vt = receiver tank volume (CF) Z, = CNG supercompressibility factor at the start of recharge T, = gas temperature in the receiver tank at the start of recharge Pb = base pressure (14.69 PSIA for West Texas) The method of the invention is explained below in relation to FIGS. 2A 2B, 2C and 2D within the context of the apparatus described above with respect to FIG 1. Once the hose connection has been established between the pressurized gas source 12 and the receiver tank 14 (and that the vehicle and the connections of the control system have been interconnected if one of the particular alternative data transmitters of the FIG 1) and the valve 45 is open, the computer 38 confirms thanks to the list of vehicles retained in its memory that the vehicle is an authorized user, sends a message to the screen 40 that says "Unauthorized user" in case of not being.
Once the authorization is confirmed, the computer 38 reads in its memory or receives from the data module of the vehicle 32 of the receiver tank 14, the volume of water and the pressure ratio (preferably the maximum permissible pressure and the maximum operating pressure). are given by the manufacturer) for the receiver tank 14. The computer 38 then calculates the volume ofCNG that can receive the tank 14 at its maximum operating pressure at 70 F, reads the initial temperature in the receiver tank 14 determined by the temperature transducer 22 and the initial pressure determined by the pressure transducer 24, calculates the initial volume of gas in the receiver tank 14 using the tank water volume and the tank initial temperature and pressure, estimates the pressure and final temperature for the receiver tank 14, instructs the solenoid 28 to open the valve 20, and tells the pressurized gas source 12 starting the rapid filling of the receiver tank 14. During the recharging of the receiver tank 1, the temperature transducer 22 and the temperature transducer 24 continue to transmit the real-time data of temperature and pressure to the computer 38, which periodically recalculates the volume of gas inside the receiver tank 14 in standard cubic feet (cubic feet under standard conditions) at predetermined intervals ados. The computer 38 compares the calculated volume as a function of the temperature and the pressure in real time inside the receiver tank14, against the previous calculation of the volume of gas that the receiver tank can support at its maximum permissible operating pressure at 70 F. If the actual volume of gas is still low, the computer 38 calculates a new temperature and estimated final pressure and determines in any case if the actual tank pressure is within some predetermined ranges, preferably around 200 psi, of the new final pressure estimate. If the tank pressure is still not within the range, the fast filling continues and the computer 38 reads the new temperature and pressure data in real time and calculates the volume of gas inside the receiver tank 14, repeating the previous steps. (The set predetermined range of about 200 psi seems to be a satisfactory value to be used in the method of the invention where a motorized storage tank is being filled at a fast filling rate of around 200cfm.) If, on the other hand, the pressure in the receiver tank 14 is already within 200 psi of the final pressure re-estimated, then the computer 38 determines whether the actual volume of gas in the receiver tank 14 is within some predetermined ranges, of preference to around 1.5%, of the volume that the tank can support in its range at 70 F. (The value of 1.5% is derived from the combined error ranges of the temperature transducer 22 and the pressure transducer 24.) If the The volume of gas inside the receiver tank 14 is within 1.5%, the computer 38 tells the solenoid 28 to close the valve 20. If it is not within 1.5%, the computer 38 again reads the pressure and temperature in time of the receiver tank 14, calculates a new temperature and final pressure estimate, and sends a signal to the pressurized gas source12 to change from "fast filling" to "slow filling." As mentioned above, the people familiar with the operation will understand when reading this information that the terms "fast filling" and "slow filling" are simply considered as relative terms and that the particular flow relationship associated with the terms may vary according to the capabilities of the equipment used. While the concepts of using a two-row recharging speed or a reduction in flow velocity while the volume of gas inside the receiving tank 14 approaches its maximum capacity are desirable for use in the current invention, the Particularly for a particular application, it is not critical for the ingenious method of controlling a system for dispensing pressurized gas based on the pressure and internal temperature of the receiver tank. It will also be appreciated upon reading this information that the hardware configurations except those described above in relation to FIG. 1 can be used to implement the method of the invention. It is emphasized for safety reasons that the estimated final pressure should always be less than the maximum allowable pressure given by the manufacturer for the receiver tank 14 and that computer system 38 will generate a signal for the solenoid 28 to close the supply valve 20 at the time when the pressure measured by the pressure transducer 24 exceeds the maximum allowable pressure given by the manufacturer for the receiver tank 14, when it is adjusted to the actual temperature of the current tank as indicated by the temperature transducer 22 to the interior of the tank 14. During the "slow filling" stage in the selected CNG dispatch operation, the computer 38 again reads the pressure and temperature in real time from the temperature transducer 22 and the pressure transducer 24, recalculates the volume of gas in receiver tank 14 in standard cubic feet using the actual tank temperature and pressure, and again determined in any case if the actual gas volume inside the receiver tank 14 is within 1.5% of the standard volume condition (pressure ratio at 70 ° F). When the receiver tank 14 has been filled to the desired level, the computer 38 calculates the final volume of gas inside the tank and subtracts the initial volume to determine the volume of gas delivered. Additional computations can be made with respect to fuel usage, mileage, cost etc, and the resulting data can be displayed as desired, stored electronically, or transmitted to the vehicle data module 32 by a firm connection as alternately presented to the vehicle. inside dotted line 48 in FIG. 1, or by another transmitter and receiver not illustrated in FIG. 1 . The three-way vent valve 45 then rotates to the vent position, releasing gas from the hose connector assembly 18 via the vent pipe 88 as illustrated in FIG. 8 to allow manual separation of male and female connectors 56, 54. The check valves arranged within the hose connector assembly 18 prevent the loss of pressurized gas from the interior of the receiver tank 14 when the hose connector assembly 18 is disconnected. According to another feature of the invention, a system and method are also disclosed for "slow filling" or "time-filling" (here used as synonymous terms) simultaneously of a variety of receiving tanks with a pressurized gas through a variety of connected hoses to the unique multiple. Such a system could be used, for example by a fast operator in situations where numerous vehicles equipped with receiving tanks with basically the same pressure ranges are stored and serviced in a common area at night. Because the receiving tanks are filled more slowly than with the particularity of the previously described invention, the adiabatic heat dissipated through the walls of the tank and the temperature of the gas inside the receiving tanks remains close to the ambient temperature. Because tank sizes and initial recharge levels are likely to vary from vehicle to vehicle, however, it is preferable to provide each receiver tank with pressure and temperature transducers to allow the calculation of final and initial gas volumes. for each tank. Referring to the particularity described in FIG. 3 of the system 100 of the invention it is preferable to have a source of pressurized gas 12 connected to a dispatch manifold 14 by gas flow line 16.; the three-way vent valves 170 and the hose connector assemblies 166 serve to establish the gas flow between the manifold 14 and the receiver tanks 160,162,164; The temperature transducers 122 disposed in each receiver tank and the temperature transducer 180 installed in the gas flow pipe 116; pressure transducers 178 installed in each receiver tank 124 and a pressure transducer 124 installed in the gas flow pipe 116; analog-to-digital converters 172; Vehicle data modules 173,174,175 for the various vehicles; RF transmitters 176; RF receivers 134; analog-to-digital converter 136; the system computer 138; the valve 120 disposed in the gas flow pipe 116 and controlled by the solenoid 128 in response to signals received from the computer 138; and a screen 140. It is preferable that the hose connector assemblies 166 are of the type described above in relation to FIG. 8, which has an RF antenna on both sides of the male and female assemblies. Although only three receiving tanks 160, 162, 164 are shown in FIG. 3, it is understood that a variety of additional tanks having basically the same pressure ranges can also be connected to the manifold pipe 15 if desired. The method by which the pressurized gas delivery system 100 is used to "slowly fill" a variety of receiver tanks is described below and explained in relation to FIGS. 4A to 4C. When the hose connector assemblies 166 have been connected to each receiver tank 160,162,164 to the dispatch manifold 14, the three-way vent valves 170 are preferably opened and the procedures for the authorization preferably initiated as discussed above in relationship to system 10 for safety reasons. At this time, the tank water volumes and pressure ratios for the receiver tanks 160, 162, 164 can be transmitted to the system computer 138 from the data modules of the vehicles 174, 175, 176 by the transmitter 176 and the receiver 136 as discussed previously in relation to system 10, or by any other similarly effective means (one of which is described below in relation to system 200 of FIG 9). The temperature and initial pressure data of the tank are also transmitted to the computer 138 from the temperature transducers 122 and the pressure transducers 178, and the computer 138 calculates the initial gas volumes for each receiving tank 160, 162 164. Then the computer 138 sends signals to solenoid 128 to open valve 120, allowing pressurized gas to flow through manifold 114, valves 170 and into receiving tanks 160, 162, 164. Because the pressurized gas entering to the manifold 114 from the pressurized gas source 112 will look for the path of least resistance, the receiver tank (s) having the lowest initial pressure will be equated (n) with the other (s) s) before the gas begins to enter the fullest tanks. As the continuous filling, the temperature and pressure data are communicated to the computer 138 by the analog-to-digital converter 136, and the computer 138 calculates the target final pressure. As soon as the pressure in the pipe has reached the target final pressure, detected by the pressure transducer 124, the computer 138 sends the signal to the solenoid 128 to close the valve 120, thereby suspending the flow of pressurized gas. The valves 170 are closed and the computer 138 reads the temperature and final tank pressure data sent by the temperature transducers 122 and by the pressure transducers 178, respectively. The computer 138 then calculates the final volume of gas for each tank and determines the volume dispatched by subtracting the initial volume. The subordinate mileage or cost data, etc., can then be generated and stored electronically, or forwarded through the means 140 (including screens, printers, tapes, disks or any combination thereof), or retransmitted to the data modules of the vehicles 173, 174, 175 by means such as those presented above in relation to the system 10. The three-way vent valves 170 then return to the venting position, releasing the gas trapped inside the hose connector assemblies 166 to allow the Manual separation of the male connectors and female connectors as described above in connection with the system 10. If desired, the system computer 138 of the system 100 can be programmed so that if the pressure, as determined by the pressure transducer 124, falls to a predetermined amount (as could happen due to gradual cooling) prior to the moment the receiving tanks are disconnected from the system Upon recharging, the computer 138 will recalculate the estimated final pressure and send the signal to the solenoid 128 to reopen the valve 120 to resume the slow filling of the receiver tank until the newly estimated final pressure is carried out. Another particularity of the invention is described in relation to FIG. 9, which speaks of the pressurized gas delivery system 200 comprises the pressurized gas source 212, the gas flow pipe 216, the gas manifold 214, the three-way vent valves 270, the hose connector assemblies 266, terrestrial antenna 250, RF receiver 234, computer 238, analog-to-digital converter 236, display 240, solenoid 228, valve 220, pressure transducer 224 and temperature transducer 280. According to this feature of the invention, the temperature transducer does not is in direct thermal contact with the gas supply pipe 216, but is arranged to measure the ambient temperature at the recharge site, (it would be convenient that this location of the temperature transducer 20 could also be used for the temperature transducer 180 of system 100 as described above). The Earth loop antenna 250 of the system 200 is a preferred vehicle - specific authorization means that it can be buried at the entrance of the recharging area to download information such as vehicle identification, mileage, tank water volume, pressure ratio , tank temperatures and initial pressures, etc., from vehicle data modules 273 as vehicles approach the recharge area. It is preferable that at the entrance of the recharge zone an automatic gate or other equally effective means be constructed that denies entry to the recharge area to unauthorized vehicles. It is preferable that the receiving tanks 260, 262, 264 be provided with temperature transducers 222, pressure transducers 278, analog-to-digital converters 272, data modules in the vehicles 273 and RF transmitters 276. With this particularity of the hose connector assemblies 266 of the invention do not comprise RF antennas so that the final temperature and pressure data in the tank from the temperature transducers 222 and the pressure transducers 278, or any data that has not been discharged to the ground antenna of 250 are transmitted to the computer 238 from the RF transmitters 276 to the RF receivers 234 as the vehicles exit the charging area. The volume of gas dispatched is then determined by the comparison of the output data against the input data. The system 200 is configured in another way and works the same as the system 100 described above.
With the inventions disclosed here, it is now possible to dispatch pressurized gas, particularly CNG, to recharge motorized storage tanks either through an automated point-of-sale ("POS") system or through an automated fast data management system ("FDM"). ) as preferred. With both systems, a computer is used to calculate the volume of gas delivered by using formulas that involve pressure, volume and temperature ("PVT") gas ratio. For fast filling applications where adiabatic heating or other temperature changes are important, the final pressure can be updated during recharging with respect to temperature changes inside the receiver tank. The data corresponding to the vehicle identification, odometer readings, tank pressure ratio, tank pressure, tank temperature, fuel consumption, etc. can be communicated to the computer as described above through the vehicle data modules, through RF transmitters and receivers(up or down the ground), through plugs with firm connectors, or through other equally effective means. With the automated POS system, the computer can be programmed to display the sale price to the buyer through any combination of screens, prints and / or electronic data storage that is desired. With the automated FDM system, the computer can be programmed to provide the fast manager with periodic reports on the specific vehicle's performance, mileage, fuel utilization, hours of operation, etc. using the data received from the vehicle data module and from the pressure and temperature sensors placed in the vehicle tanks. The systems and methods presented here are also applicable to more advanced vehicle fuel systems that use gaseous fuels, both liquid and compressed, the reports can also be generated with respect to the operating time, amount of fuel used, and the mileage achieved with each gas. Other alterations and modifications of the invention may also become evident to those familiar with the operation, when reading the